This invention relates to a process for removing toxic quantities of heavy metals from the bloodstream and membrane apparatus for use in the process. It is already known that substantial health problems are encountered by those who build up excessive amounts of heavy metal within their bodies. Particularly well known toxic metals which are often present in contaminated environments are iron, cadmium, lead, radioactive metals, and mercury. However, physiological disorders can result in a patient building up toxic quantities of metals (iron-copper) in the bloodstream even when the environment is normal.
Many methods of treatment for heavy-metal poisoning are based on the use of specific agents which convert the metal to a chemical form in which it is relatively inert and can be readily excreted. Such treatments take time and are quite specific and, consequently, depend excessively on a precise diagnosis. They are more time consuming than is desirable.
As described below, the present invention is intended to overcome some of these problems.
Also, outer pore surface of membranes have been used to hold chemicals and catalysts by Breslau in U.S. Pat. No. 4,266,026 and various prior work cited by him in his patent. In all of this prior work, a relatively conventional flow of material through the membrane barrier layer was realized before any component within the lumen of the membrane is reacted with a catalyst or other reactant carried in the large pores.
Introduction of various chelating agents into the bloodstream of mammals has been suggested in a number of such references including several set out in the extensive bibliography attached to an article entitled "The Dialysis of Poisons and Drugs"by John F. Maher and George E. Schreiner in Volume XIV of the American Society for Artificial Internal Organs; 1968, pages 440-453. One of many such articles are those relating to canine iron intoxification and to peritoneal dialysis of a patient with ferrous sulfate poisoning, all referred to at page 445 of the above-identified article. Other articles, such as Looney et al (reference in the above-identified Maher et al reference) describe direct contact of blood, including the formed elements with the chelating material. This procedure results in undesirable absorption or rupturing of the platelets, i.e. thrombocytes. As indicated above, side effects of such direct contact with the bloodstream have prevented these procedures from becoming of general therapeutic value. Moreover like most direct chemical treatment, use of chelating agents in this way can itself cause undesirable toxic reactions, particularly to patients already weakened by metal poisoning.